Make danger PTO-emoji-aware

What does this MR do?

We advise people to use OOO in their GitLab statuses when they're away, but people also commonly use the 🌴, 🏖, ⛱, or 🏖 emoji too - and it's easy to forget to change the text, or the emoji. Let's make danger respect both, to be as forgiving as possible.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content